Flexible conduit



as, 193., A L LEA mamas FLEXIBLE GONDUIT FiledApril 19; 1955 PatentedAug. I6, 1938 I 2,i26-,%5

UNITED STATES. PA-TENT OFFICE FLEXIBLE CONDUIT George A. Gleason,Worcester, Mass, assignor to The American Steel and Wire Company of NewJersey, a corporation of New Jersey Application April 19, 1935, SerialNo. 17,325

3 Claims. (01. 64-3) This invention is an improved form of flexibleextruded onto the cable. It is also to be noted conduit of thetypefrequently used to carry the that the head portion 3 of the T-wire 3extends operating cables of automobile brakes. at least slightly abovethe outer faces of the This conduit consists of ashort-pitched helicalconvolutions of the half-round wire.

5 coilof half-round wire having its normally flat The outermost layer ofthe conduit consists of 5 face inside and upset so that it isappreciably the plurality of wires 4 which are tightly wound convex,T-wire wound over this coil with its stem with a relatively long-pitchedlay over the T-wire portion forced inwardly between the convolutions 3so as to contact the latters head portion 3 -of the half-round wire toan extent suflicient to and so as to continuously force the T-wire to atleast slightly separate the same but insuflimaintain its relationshipwith the half-round 10 cient to become flush with their inside faces andwire. The cord packing 5 is laid between the T- with its head portionextending at least slightly wire 3 and the wires 4 so as to fill theinterstices above the outer faces of these convolutions, wires betweenthe latter. Any tendency of the halftightly wound with a relativelylong-pitched lay round wire-2 or T-wire 3 to open up due to their overthe T-wire so as to contact the latters head short-pitched helical formis prevented or re- 15 portions and continuously force the .T-wire totarded by these wires 4 due to their relatively maintain itsrelationship with the half-round long pitch. Furthermore, these wires 4function wire and cord packing which is laid between the to greatlyincrease the tensile strength of the T-wire and the last mentioned wiresso as to fill conduit as a whole. They also function to contheinterstices between the latter. tinuously force the T-wire 3 into placeso that no 20 The above conduit is illustrated by the accomopenings willoccur when the conduit is arced, panying drawing, in which: this actionbeing particularly effective due to the Figure 1 shows the conduitbroken away so as fact that the head portions 3 of the T-wire 3 toillustrate its component parts; extends slightly above the outer facesof the con- Figure 2 shows the specific relationship of the volutions ofthe half-round wire 2. Since this 25 parts by means of an enlargedlongitudinal secwill in many cases make the conduit entirely tion. ggrease-tight, it will be possible to entirely elimi- Referring moreparticularly to this drawing: nate the cord packing 5 in many instances.Then Figures 1 and 2 illustrate a cable I carried by too, these wires 4may be fust-proofed by galthe conduit consisting of the short-pitchedhelical vanizing orfthe like, or they may be made of coil of half-roundwire 2 having its normally rust-resisting steel, whereby it will not benecesflat face 2 inside and upset so that it is apsary to paint orotherwise protect the conduit preciably convex. This convexity may besecured against rust. during the coiling operation providing the half-All of the wires are preferably made of high- 3 round wire 2 is ofsuiflciently large dimensions as carbon or other hard steel. Thisreduces the compared to the diameter of the helix into which wear on thehalf-round wire 2 and renders the it is formed. The convex faces thusprovided .T-wire 3. sufliciently rigid to prevent any shortenare ofgreat advantage in that they materially ing of the conduit. The longpitch of the wires 4 reduce wear on the cable I by reducing thefriceflfectively dampens the conduit so as to greatly 40 tion betweenthe parts and by preventing the retard any crystallization which mightresult 0 sharp edges of the half-round wire from exerting fromvibration. any cutting action. I claim;

The T-wire 3 is wound over the coil of half- 1. A flexible conduitincluding a short-pitched round wire 2 with its stem portion 3 forcedhelical coil of half-round wire having its flat inwardly between theconvolutions of the latter face inside, T-wire wound over said coil withits 45 to an extent sufiicient to at least slightly sepstem portionextending inwardly between the arate the same but insufficient to itselfbecome convolutions of said half-round wire and its head flush withtheir inside faces 2. This separation portion extending at leastslightly above said of the convolutions provides an internal helicalconvolutions and wires tightly laid with a relagroove for the conduit,which function'sas a tively long pitch over said T-wire so as to contact50 grease retainer from which grease may be dissaid head portion andcontinuously force said 1'- tributed to the cable] during the lattersreciprowire inwardly. eating action.- Furthermore, any flexing of the 2.A flexible conduit including half-round wire conduit tends to close thisgroove at one point of such dimensions and coiled into a helix of suchor another whereby any grease in the same is diameter, with its normallyflat face inside, as.

" to cause said face to be upset into a convex taco,

T-wire wound over said helix with its stem portion extending inwardlybetween the convolutions of said halt-round wire and its head portionextending at least slightly above the outsides of said convolutions andwire wound over said convolutions oi. the head portion of said T-wire soas to apply pressure to'the same, the last named wire having a lonerpitch than said halt-round wire and said T-wiro whereby it crosses thelatter at an angle.

- GEORGE A. GLEABON.

